US8268124B2 - Method for production of pulp - Google Patents

Method for production of pulp Download PDF

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Publication number
US8268124B2
US8268124B2 US12/450,168 US45016808A US8268124B2 US 8268124 B2 US8268124 B2 US 8268124B2 US 45016808 A US45016808 A US 45016808A US 8268124 B2 US8268124 B2 US 8268124B2
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Prior art keywords
wood chips
pulp
caustic soda
production process
aqueous solution
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Expired - Fee Related, expires
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US12/450,168
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US20100175841A1 (en
Inventor
Akira Ako
Kazumasa Koike
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Nihon Cellulose Co Ltd
Toa Kogyo Co Ltd
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Nihon Cellulose Co Ltd
Toa Kogyo Co Ltd
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Assigned to KABUSHIKI KAISHA TOA KOGYO, NIHON CELLULOSE CO., LTD. reassignment KABUSHIKI KAISHA TOA KOGYO ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: AKO, AKIRA, KOIKE, KAZUMASA
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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C1/00—Pretreatment of the finely-divided materials before digesting
    • D21C1/06—Pretreatment of the finely-divided materials before digesting with alkaline reacting compounds
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/02—Pulping cellulose-containing materials with inorganic bases or alkaline reacting compounds, e.g. sulfate processes
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/04—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides
    • D21C3/16—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides nitrogen oxides; nitric acid nitrates, nitrites

Definitions

  • the present invention relates to a pulp production process that can production pulp at high yield without using sodium sulfide and high-temperature/high-pressure conditions if compared with the Kraft process and also collect lignin.
  • the present invention is aimed at utilization of lumber originating from buildings (wood debris from demolished wooden buildings, scrap wood from buildings, waste furniture and so on) as material for producing pulp.
  • the Kyoto Protocol was voted in 1997 according to the United Nations Framework Convention on climate Change and the target reduction ratios of the developed countries were determined relative to the reference emission levels of 1990 for carbon dioxide, methane, nitrogen monoxide, HFCs and sulfur hexafluoride. The target values are to be achieved by the jointly set time limit.
  • the Kyoto Protocol was ratified by the Japanese Diet on May 31, 2002 and Japan deposited the instrument of acceptance in the United Nations on Jun. 4, 2004.
  • the determined target reduction ratios from the year of 2008 to the year of 2012 include 6% for Japan, 7% for United States of America and 8% for the European Union.
  • the present invention is intended to respond to the above-identified demand of the international society.
  • the target recycling ratio is set to 95% including reduced (incinerated) wood.
  • Such wood is currently recycled after being crushed to wood chips in order to produce boards for particles, raw materials for paper producing, compost and so on and also for applications including mulching, thermal recycling (fuel) and chemical recycling.
  • improper deposits (illegal dumping) of wood waste are frequently observed and fires have sometimes broken out as a result of spontaneous ignition of wood waste.
  • Wood is the most popular material that is being used in houses. However, many wood plates including those used for repairing are cross-laminated plates prepared by using paint and adhesive and hence can hardly be recycled to produce materials. In other words, most of them are thermally recycled (as fuel).
  • Lumber originating from construction work amounts to 9,000,000 tons per year only in the Kanto District in Japan.
  • wood waste is not reduced (incinerated) by thermal recycling but utilized as raw material for paper producing, a forest area that is two to three times as large as the forest area that needs to be destroyed to produce wood can be conserved on this planet because paper can be recycled two to three times. Then, the effect of supplying oxygen and suppressing carbon dioxide gas can be doubled or tripled.
  • the Kraft process takes about 95% of the overall pulp production in the world, using wood chips as principal raw material.
  • water, caustic soda and sodium sulfide are added to wood chips mainly obtained by crushing lumber cut out from woods to make them show a certain ratio and the materials are cooked (boiled) in a vessel at an average temperature of 160° C. under 6 to 7 atm for not less than 3 hours.
  • lignin that operates to bond the cellulose contained in the wood chips is continuously dissolved into the solution to isolate cellulose and hemicellulose from each other and produce pulp as lump of cellulose.
  • the obtained pulp is generally referred to as fresh pulp. This process is the best pulp producing process in terms of cost performance at present.
  • Chips are sorted to make them show a thickness and a length that are found respectively within certain ranges and the dust is removed from them so that they may be cooked and digested uniformly.
  • the solution of the chemicals (caustic soda and sodium sulfide) containing the lignin dissolved in it (black liquor) is separated from the pulp, which is then washed with water.
  • the lignin remaining in the pulp is eluted by means of oxygen and alkali.
  • the foreign materials such as dirt contained in the pulp is isolated and removed.
  • the pulp is bleached by means of a chemical selected from chlorine, chlorine dioxide, oxygen, caustic soda and sodium hypochlorite.
  • the black liquor is concentrated.
  • the concentrated black liquor used as fuel within the process and collected as sodium carbonate.
  • Patent Document 1 describes a process of turning green liquor, caustic.
  • Patent Document 2 describes a process of bleaching pulp.
  • Patent Document 3 describes a PA process (hydrogen peroxide-alkali process) where hydrogen peroxide, a caustic alkali and a small amount of digestion promoter are used. It tells that hydrogen peroxide shows a delignification effect.
  • Patent Document 4 describes that a surfactant and a chelating agent are added when bleaching chemical pulp by ozone.
  • Patent Document 5 describes a process of bleaching pulp showing a high viscosity relative to permanganate number.
  • the process is for producing high-quality pulp exclusively from high-quality wood chips and hence is not related to producing pulp from lumber originating from construction work. Additionally, it produces carbon dioxide gas to a large extent.
  • the above object is achieved as by providing a novel pulp production process as defined below.
  • a pulp production process characterized by comprising:
  • a digested pulp/black liquor separating step of filtering the product of digestion obtained as a result of said digesting step and separating digested pulp and lignin-containing black liquor from each other.
  • a pulp production process characterized by comprising:
  • hydrophilicizing step of hydrophilicizing 1 weight portion of wood chips by immersing it in 5 to 20 weight portions of a caustic soda aqueous solution with a concentration of 1 to 10 wt % at 1.5 to 40° C. for 10 to 60 hours;
  • an oxidizing step of selectively partially oxidizing the lignin contained in the wood chips at 80 to 98° C. for 40 to 120 minutes by adding 3 to 15 weight portions of a nitric acid aqueous solution with a concentration of 1 to 10 wt % to 1 weight portion of the first washed wood chips obtained as a result of said first washing step;
  • a digested pulp/black liquor separating step of filtering the product of digestion obtained as a result of said digesting step and separating digested pulp and lignin-containing black liquor from each other.
  • a pulp production process as defined in (1) or (2) above is characterized in that the hydrophilicizing step, the oxidizing step and/or the digesting step are conducted under low pressure (e.g., 1 to 2 atm).
  • a pulp production process as defined in any one of (1) through (3) above is characterized in that the digesting step is divided in a first stage digesting step and a second stage digesting step and the first stage digesting step employs an caustic soda aqueous solution with a caustic soda concentration lower than the caustic soda aqueous solution that the second digesting step employs.
  • a pulp production process as defined in any one of (1) through (4) above is characterized in that hot water is introduced after the oxidizing step to accelerate the oxidizing reaction rate of nitric acid so as to completely consume the nitric acid.
  • a pulp production process as defined in any one of (1) through (5) above is characterized in that wood chips are those of lumber of one or more types including lumber obtained by cutting trees in forests, lumber from thinning and lumber originating from construction work.
  • a pulp production process as defined in any one of (1) through (6) above is characterized in that lignin is agglomerated and sorted out from the lignin-containing black liquor.
  • the present invention provides a pulp production process that may not use lumber originating from construction work and does not require a pressure vessel nor use pollutants such as sulfides, consuming water only at a small rate while not using lignin as fuel.
  • FIG. 1 is a schematic view of flowchart of the Kraft process.
  • FIG. 2 is a schematic view of flowchart of a process according to the present invention.
  • FIG. 3 is schematic view of another flowchart of a process according to the present invention.
  • Sodium sulfide is added to the digesting step of the Kraft process by means of a high-concentration caustic soda aqueous solution and lignin is processed at high temperature under high pressure so as to be oligomerized and prevented from being polymerized back by sodium sulfide.
  • Caustic soda dissolves lignin and is consumed to neutralize organic acids and saponify the resin content.
  • lignin is selectively oligomerized by means of a dilute nitric acid aqueous solution that operates as strong oxidant prior to the digesting step and a dilute caustic soda aqueous solution is employed for the digesting step under mild conditions including the atmospheric pressure and a low temperature below the boiling point in order to elute lignin, while preventing the lignin from being further oligomerized, so as to allow lignin from being condensed and separated from the black liquor.
  • chip size may vary depending on the type thereof, it is within a range suitable for being processed by chemical solutions (several millimeters to tens of several millimeters).
  • wood chips obtained by crushing lumber is immersed into a dilute caustic soda aqueous solution (with a concentration preferably of 1 to 10 wt %, more preferably of 1 to 5 wt %) at room temperature under the atmospheric pressure for tens of several hours (preferably 10 to 50 hours).
  • the concentration of the dilute caustic soda aqueous solution is preferably 1 to 10 wt %.
  • the desired effect is not achieved when the concentration is less than 1 wt %, whereas the load of the subsequent washing step is raised when the concentration exceeds 10 wt % because dilute nitric acid is employed in the washing step.
  • the hydrophilicizing operation of the hydrophilicizing step is facilitated when the chips are immersed in water prior to processing them by means of a dilute caustic soda aqueous solution.
  • the alkali component is preferably thoroughly removed for the oxidizing operation in the subsequent oxidizing step:
  • the hydrophilicized chips are immersed in a dilute nitric acid aqueous solution (with a concentration preferably of 1 to 10 wt %) to selectively partially oxidize lignin and encourage oxidation/decomposition and oligomerization thereof.
  • Dilute nitric acid shows a strong oxidizing effect as indicated by the reaction formula shown below: 2HNO 3 ⁇ 2NO+5[O]+H 2 O, where [O] represents an oxygen radical (active oxygen) that is highly reactive and has a very short life.
  • the stains operate as catalyst to accelerate the reaction by heating. Additionally, since the reaction proceeds very fast at about 80° C., the oxidizing condition in the oxidizing step can be maintained in a well controlled manner throughout the oxidizing step when pulp and dilute nitric acid are introduced into the oxidizing process at room temperature and subsequently raising the temperature to about 98° C.
  • O 2 and NO 2 are produced by a side reaction of [O] and gas containing NO and NO 2 is collected from the top of the vessel.
  • NO x nitrogen oxides
  • the Ostwald process is known as industrial process for producing nitric acid that proceeds as shown below. 2NO+O 2 ⁇ 2NO 2 3NO 2 +H 2 O ⁇ 2HNO 3 +NO (NO is recycled)
  • the NO and NO 2 produced by this step can be collected under the form of nitric acid by employing the Ostwald process.
  • hot water is preferably introduced at the end of the oxidizing step for the purpose of heating in order to completely conclude the reaction of decomposing nitric acid.
  • the residual nitric acid, if any, is substantially completely consumed for the reaction and hence eliminated.
  • Lignin is scarcely eluted in the oxidizing step.
  • the NO and NO 2 that are produced in this step are collected with those of the preceding step.
  • chips are separated the eluted small-amount lignin and drug solution from each other, and is washed with water.
  • chips and a dilute caustic soda aqueous solution are heated (preferably at 95 to 100° C. for 30 to 120 minutes) to dissolve lignin.
  • the caustic soda aqueous solution dissolves lignin and also is consumed to neutralize organic acids and saponify the resin contents.
  • the duration of the digesting step is more preferably 30 to 60 minutes.
  • All the contained lignin is substantially dissolved (by not less than 95%) in this step.
  • the concentration of dilute caustic soda aqueous solution is more preferably 1 to 10 wt %.
  • the process of dissolving lignin practically does not proceed when the concentration is less than 1 wt %, whereas lignin is dissolved without any problem but caustic soda is discharged as waste that does not take part in the reaction and/or the lignin concentration becomes too high in the black liquor to obstruct the process of agglomerating and sorting out lignin from the black liquor when the concentration exceeds 10 wt %.
  • the digested pulp and the black liquor are separated from each other and the pulp is washed with water in the subsequent washing step before the lignin is fed to the next step.
  • the black liquor contains lignin to a concentration of not more than several %
  • lignin can be sorted out with ease by agglomerating because the lignin concentration in the black liquor is low.
  • the known process can be applied to the digested pulp.
  • the lignin and the oxygen remaining in the pulp are eluted further, by means of alkali.
  • the foreign materials such as dirt is isolated and removed.
  • the pulp is bleached by means of a chemical selected from chlorine, chlorine dioxide, oxygen, caustic soda and sodium hypochlorite.
  • lignin is agglomerated, sorted out and recycled as resource.
  • An electrolytic treatment technique and a water treatment technique can be applied for the purpose of treating waste water and collecting chemicals.
  • Organic substances are sorted out and recycled as resource.
  • Water, sodium and chlorine also can be recycled by applying an electrolytic treatment technique.
  • Lumber (veneer) was roughly crushed by means of a crushing machine (not shown) containing rotary claws and further crushed secondarily. Then, wood chips with a size not greater than 50 mm were sorted out from the crushed product. They were repeatedly subjected to a crushing/sorting operation until the obtained wood chips showed a size of 3 to 15 mm. In this way, desired wood chips were prepared.
  • the wood chips were immersed in a dilute caustic soda aqueous solution with a concentration of 5 wt %.
  • the solution temperature was held to the room temperature and the step was continued for 50 hours.
  • the oxidation treatment tank is a vessel that can be hermetically sealed.
  • the hydrophilic-treated chips were put into an oxidation treatment tank with a dilute nitric acid aqueous solution showing a concentration of 5 wt % at room temperature and steam was blown in from below.
  • the mixture was heated and agitated slowly for an oxidizing process.
  • the internal temperature of the treatment tank got to 80° C. after 40 minutes. Bubbles were generated fiercely as the internal temperature of the treatment tank rose and the heating was suspended temporarily when the bubbling was too fierce. Gas containing NO was collected from an upper part of the oxidation treatment tank.
  • lignin was selectively partially oxidized, the quantity of eluted lignin was small.
  • Hot water was added and the inside of the treatment tank was heated to continue the oxidizing process. Bubbles started to be generated when the process temperature got to 98° C. and the reaction came to end.
  • the chips produced after the oxidizing process was washed put into a digestive tank with a caustic soda aqueous solution with a concentration of 5 wt % and steam was blow into the digestive tank from below.
  • the mixture was boiled and agitated. The process was made to continue for an hour after the process temperature got to 98° C.
  • the digested pulp and the black liquor were separated from each other. While lignin was agglomerated and sorted out from the black liquor, the lignin contained in the chips was eluted by not less than 95%.
  • the lignin remaining in the pulp were eluted further by means of oxygen and alkali and the pulp was bleached in the bleaching step by means of sodium hypochlorite.
  • the pulp obtained as a result was equivalent to pulp that can be obtained by means of the Kraft process.
  • the foreign materials such as dirt contained in the pulp were separated from the latter in the filtering/refining step.
  • Paper was produced by means of the pulp obtained in this example and subjected to a test. Tables 1 and 2 summarily illustrate the obtained results.

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US12/450,168 2007-01-15 2008-01-15 Method for production of pulp Expired - Fee Related US8268124B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2007-006159 2007-01-15
JP2007006159 2007-01-15
PCT/JP2008/051008 WO2008088077A1 (ja) 2007-01-15 2008-01-15 パルプの製造方法

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US20100175841A1 US20100175841A1 (en) 2010-07-15
US8268124B2 true US8268124B2 (en) 2012-09-18

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US (1) US8268124B2 (ja)
EP (1) EP2151521A1 (ja)
JP (1) JP5360546B2 (ja)
CN (1) CN101675190B (ja)
CA (1) CA2681464C (ja)
MY (1) MY148826A (ja)
WO (1) WO2008088077A1 (ja)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4604136B1 (ja) * 2009-06-16 2010-12-22 株式会社 東亜興業 パルプ製造装置、パルプ製造方法及び高濃度パルパー
JP2011001677A (ja) * 2010-01-08 2011-01-06 Toa Kogyo:Kk パルプ製造装置、パルプ製造方法及び高濃度パルパー
CN103464105B (zh) * 2013-10-12 2015-02-18 山东佳源空调设备有限公司 一种锯末制备酸性废水吸附剂的方法
CN105821691B (zh) * 2016-03-29 2017-05-31 厦门壳氏新材料科技有限公司 一种除去稻壳杂质的方法
JP2018188502A (ja) * 2017-04-28 2018-11-29 フラーレン事業協同組合 木質チップ又は繊維質植物粉砕体からパルプ及びリグニンを回収するｎｃ回収方法
HRP20190259A2 (hr) * 2019-02-07 2020-08-21 Marinko Mikulić Kontinuirani postupak proizvodnje celulozne pulpe iz travnatih sirovina
CN113529495B (zh) * 2021-07-22 2023-03-24 广西大学 一种高水稳定性的生物质基餐具的制备方法
CN113580668B (zh) * 2021-07-22 2023-05-30 广西大学 一种自粘合和水稳定性的纸吸管的制备方法

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US2110545A (en) * 1934-05-16 1938-03-08 Dreyfus Henry Treatment of cellulosic materials
JPS58132188A (ja) 1982-01-26 1983-08-06 山陽国策パルプ株式会社 木材チツプの蒸解前処理方法
US4652341A (en) * 1980-08-07 1987-03-24 Prior Eric S Accelerated pulping process
JPH05163690A (ja) 1991-05-24 1993-06-29 Kamyr Inc クラフトパルプの製造方法
WO1999007936A1 (en) 1997-08-07 1999-02-18 Ahlstrom Machinery, Inc. Continuous cooking with cool impregnation and dom control
JP2004169203A (ja) 2002-11-19 2004-06-17 Nippon Paper Industries Co Ltd 高白色度漂白クラフトパルプの製造方法
JP2004169205A (ja) 2002-11-19 2004-06-17 Nippon Paper Industries Co Ltd 高白色度漂白クラフトパルプの製造方法
JP2004169204A (ja) 2002-11-19 2004-06-17 Nippon Paper Industries Co Ltd 高白色度漂白クラフトパルプの製造方法
JP2004256925A (ja) 2003-02-24 2004-09-16 Nippon Paper Industries Co Ltd 木材チップ前処理方法および高白色度クラフトパルプ製造方法

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EP0665912B1 (en) 1992-10-23 1998-02-11 Macmillan Bloedel Limited Improved ozone bleaching
JPH08188976A (ja) 1995-01-09 1996-07-23 Mitsubishi Paper Mills Ltd 化学パルプのオゾン漂白
JPH11286884A (ja) 1998-04-03 1999-10-19 Akio Onda パルプ蒸解薬液とパルプの製造方法
JP2001172888A (ja) 1999-12-15 2001-06-26 Toyota Central Res & Dev Lab Inc 紙パルプ処理方法
CN1410627A (zh) * 2002-09-16 2003-04-16 成都春天绿竹资源开发有限责任公司 纯天然抗菌竹浆的生产工艺
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Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2110545A (en) * 1934-05-16 1938-03-08 Dreyfus Henry Treatment of cellulosic materials
US4652341A (en) * 1980-08-07 1987-03-24 Prior Eric S Accelerated pulping process
JPS58132188A (ja) 1982-01-26 1983-08-06 山陽国策パルプ株式会社 木材チツプの蒸解前処理方法
JPH05163690A (ja) 1991-05-24 1993-06-29 Kamyr Inc クラフトパルプの製造方法
WO1999007936A1 (en) 1997-08-07 1999-02-18 Ahlstrom Machinery, Inc. Continuous cooking with cool impregnation and dom control
JP2004169203A (ja) 2002-11-19 2004-06-17 Nippon Paper Industries Co Ltd 高白色度漂白クラフトパルプの製造方法
JP2004169205A (ja) 2002-11-19 2004-06-17 Nippon Paper Industries Co Ltd 高白色度漂白クラフトパルプの製造方法
JP2004169204A (ja) 2002-11-19 2004-06-17 Nippon Paper Industries Co Ltd 高白色度漂白クラフトパルプの製造方法
JP2004256925A (ja) 2003-02-24 2004-09-16 Nippon Paper Industries Co Ltd 木材チップ前処理方法および高白色度クラフトパルプ製造方法

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JPWO2008088077A1 (ja) 2010-05-13
CN101675190A (zh) 2010-03-17
EP2151521A1 (en) 2010-02-10
CA2681464C (en) 2017-01-03
US20100175841A1 (en) 2010-07-15
WO2008088077A1 (ja) 2008-07-24
CN101675190B (zh) 2012-02-01
MY148826A (en) 2013-06-14
JP5360546B2 (ja) 2013-12-04
CA2681464A1 (en) 2008-07-24

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